In this paper, high frequency impedance analysis of an electrochemical quartz crystal microbalance is employed to monitor changes in the viscoelastic properties of conducting polymers. The frequency and motional inductance sensitivity measured during the electrodeposition of Cu, Ag and polypyrrole(tosylate) is compared with the theory for various quartz crystals of different cuts and fundamental resonant frequencies. It is found that changes in resonant resistance do not significantly depend on the quartzes used. It is shown that this technique is particularly appropriate for probe disparities in the morphology of conducting polymer films depending on the solvent, the size of the counteranion or the substrate. Changes in the viscoelastic properties of polypyrrole(tosylate) films up to 200-degrees-C were also investigated.